1. Field of the Invention
The present invention relates to an attitude correction apparatus including opposing laser emitters for correcting the attitude of an object such as a head suspension installed in a hard disk drive.
2. Description of Related Art
Recent hard disk drives employ hard disks of very high recording density, and due to this, a head suspension that supports a magnetic head to read/write the hard disk in the hard disk drive is required to be highly precise. The magnetic head attached to the head suspension floats from the hard disk by a predetermined distance when the hard disk is driven at high speed and the attitude of the floating magnetic head is greatly influenced by a minute difference in attitude angles such as roll and pitch angles of the head suspension.
Accordingly, attitude angles of every head suspension must be corrected with the use of an attitude correction apparatus in a manufacturing line.
An example of the attitude correction apparatus is disclosed in Japanese Unexamined Patent Application Publication No. 2007-66427. This related art emits a laser beam to a correction object, i.e., a head suspension to thermally deform the laser-irradiated part and correct the attitude of the head suspension.
This related art arranges a pair of laser emitters on each side of a head suspension and emits laser beams from the laser emitters to each side of the head suspension, thereby correcting the attitude of the head suspension. This technique is capable of shortening an attitude correction time, increasing an attitude correction amount, and improving an attitude correction accuracy.
The related art, however, has a problem that, if one of the laser emitters accidentally emits a laser beam in a standby state into the other laser emitter, an optical isolator, a light source, and the like arranged in the other laser emitter are damaged. If the laser emitters are fiber lasers that achieve high gain, the laser emitter that accidentally receives a laser beam from the other intensifies the received laser beam and the optical isolator, light source, and the like thereof are severely damaged.